Contact insertion turret end effector

ABSTRACT

A first end effector extends from a rotatable support in a first direction and has a tip portion extending in a second direction transverse to the first direction, and a second type of end effector extends in a third direction and has a tip portion extending in a fourth direction opposite the second direction, to enable contact insertion into a connector by either effector and regardless of the orientation in space of the connector.

STATEMENT OF GOVERNMENT INTEREST

The invention described herein may be manufactured and used by or forthe Government for governmental purposes without the payment of anyroyalty thereon.

BACKGROUND OF THE INVENTION

The present invention relates to the field of contact insertion endeffectors.

Various types of end effectors are known in the art for insertingcontacts into electrical connectors. Due to a wide variety ofcircumstances confronted when performing a contact insertion, a firsttype of end effector will operate reliably under a first set ofconditions whereas a second type of end effector will be more desirableunder different circumstances.

For example, a double pinch-push contact insertion end effector does notenter the connector and performs a contact insertion by progressivelywalking the contact into the connector. See for example my U.S. Pat. No.4,598,469 for a detailed description of such an end effector. A tendencyfor the wire to buckle during insertion occurs, particularly where thewire is thin or the required insertion forces are considerable, when thewire is being pushed through a rubber grommet for example. Under thesecircumstances, a second type of insertion tool is more desirable, whichpushes against the lip of the contact rather than walking the wire intothe connector in the manner of the double pinch-push insertion endeffector. However these insertion tools are more fragile than thepinch-push effectors. For a further discussion of insertion tool endeffectors, reference may be made to my Statutory Invention RegistrationNo. H225.

SUMMARY OF THE INVENTION

It is thus a principal object of the invention to easily and rapidlyselectively position one of two types of end-effectors against theconnector, regardless of the position in space of the connector.

This object of the invention is attained by providing first and secondtypes of end effectors which are mounted in a back-to-back relationshipupon a rotatable support device, which in turn is rotated by a motor toselectively position one of the end effectors in any position in spacerelative to a connector receiving contacts manipulated by the endeffectors. A digital closed loop motor control circuit is provided forsensing and eliminating counter-rotation of an end effector during theinsertion process, which would otherwise be produced by reaction forcesof the connector against the tip of the active end effector.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the invention will becomeapparent upon study of the following detailed description taken inconjunction with FIGS. 1 and 2 which illustrate a preferred embodimentof the invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

As shown in FIGS. 1 and 2, support 5 is utilized to support a rotatableend effector support means 2 having a first contact insertion endeffector 1 mounted thereon, together with a second contact insertion endeffector 3, mounted in a back-to-back relationship with respect to thefirst one. The rotatable support rotates about rotation axis 4coincident with the rotation axis of gear 6 which is coupled to D.C.servo motor 9 via a second gear 11. Effector 1 preferably comprises theaforesaid double pinch-push contact insertion end effector, whileeffector 3 comprises the insertion type end effector. The insertion tipportion 31 comprises JAW A and extends in a direction substantiallyperpendicular to the elongated end effector 1 and tip portion 32 or JAWB of the insertion effector 3, extends perpendicular to end effector 3.The motor control means utilizes a digital closed loop feedback controlcircuit well known to workers in the art, and employs an analog todigital encoder disk 17 which is affixed to a shaft 19 driven by a gear6. A conventional read head 21 is utilized to read the code in thevarious tracks of the circular disk to produce a binary code on leads22, indicative of the absolute angular position of disk 17 and hence theangular position of the end effectors with respect to rotational axis 4.

Let it be assumed that JAW A is presently in the vertical positionindicated by dotted lines at the right hand portion of FIG. 2. Connector36 is to receive a contact driven by JAW A in a horizontal direction.Position address circuit 15 then generates a binary code indicative of a90° rotation of effector 1 so as to position it as shown as solid linesat the bottom of FIG. 2. The motor control circuit 13 causes a currentto pass through servo motor 9 to cause it to drive gears 11 and 6 androtate the support device 2 until the binary code adjacent read head 21indicates that a 90° rotation (clockwise) of rotatable support 2 hasbeen produced. A comparator within motor control circuit 13 thusindicates a match between the position read by read head 21 and theaddress code produced by circuit 15, which reduces the current fed intothe armature of servo motor 9 to cause JAW A to stop adjacent thevertically oriented side portion 38 of connector 36.

Since the details of the operation of the double pinch-push contactinsertion end effector form no part of the present invention, referenceshould be made to my U.S. Pat. No. 4,598,469 for details of theoperation of the end effector. As described in this patent, pneumaticair cylinders assert insertion forces against the wire contacts to bedriven into the side of connector 36, such insertion forces beingrepresented by the arrow labeled FI at the bottom of FIG. 2. Howeverthis causes a reaction force FR to be produced which causes the endeffector to rotate in a counter clockwise direction represented by arrowTR about rotational axis 4. This causes a problem which is solved inaccordance with the present invention. The rotation TR, following thetorque producing by the force FI, causes a slight rotation of disk 17 inthe opposite (counter clockwise) direction and the change in the digitalcode is sensed as a mismatch by the comparator of motor control circuit13, which in turn increases the current flowing through the armature ofmotor 9 to produce a torque TI in a clockwise direction to maintain theJAW A in its proper position with respect to the vertically orientedconnector 36. In other words, the mismatch at the comparator of controlcircuit 13 causes the motor to be driven again in a clockwise direction,as it was during the positioning of the end effector 1 from thehorizontal position mentioned above to the vertical position againstconnector 36. In the interest of brevity, further details of circuit 13will not be described since they are widely known and utilized byworkers in the art.

Should it be desired to insert the wire contact in face 38 of connector36 which may be horizontally oriented, end effector 1 would be driven tothe position shown in dotted lines at the right hand portion of FIG. 2;any angular orientation of the face of connector 36 may be accommodatedby appropriately angularly positioning the effector at the requiredangle. Should the second type of end effector such as the insertion typebe utilized, the horizontally oriented JAW B would be moved 180° aboutaxis 4, so that it is situated in the same position relative to thevertically oriented connector 36 as JAW A was previously. Thus it shouldbe understood that either type of end effector may be positioned withrespect to connector 36, regardless of its orientation in space, as thetip portions of the end effectors assume diametrically oppositepositions with respect to rotational axis 4 and extend in oppositedirections with respect to each other to enable simplified motor drivein one direction only, and for inserting wire contacts into connectorsregardless of their orientation in space. The aforesaid closed loopmotor control circuit is utilized to prevent the reaction forces fromcounter-rotating the end effectors away from the connectors.

It is understood that numerous variation may be made in the aforesaidembodiment and thus the scope of the invention is to be limited only bythe terms of the following claims and art recognized equivalentsthereof.

What is claimed is:
 1. An electrical contact end effector machinecomprising:a. rotatable end effector support means having a rotationalaxis; b. a first contact insertion end effector mounted upon saidsupport means; c. a second contact insertion end effector mounted uponsaid support means; d. motor means for rotating said rotatable endeffector support means to cause either said first end effector or saidsecond end effector to assume a desired orientation with respect to anelectrical connector; and e. motor control means for actuating saidmotor.